384 hp / 421 tq: DINAN 135i Tuning

[WhereItsAt]

Water cooled turbos would be good. I secondary oil cooler (efficient and preferably less than $2000) with a thermostat is likely the best bandaid.

EDIT = A secondary water cooler for the Turbos. Again my multitasking = the fail

[chemhalo]

Greddy sells quite a few very large oil coolers for Supra's etc. If I remember right they run $500-600 depending on the application. With the right fittings and some mounts, no reason one couldnt be popped in.

[mkiiieustyle]

i have seen alot of open deck engine make good power, but like said before it is a limiting factor, simple deck rings can be pressed in, honda's use them alot when boostin d+b series motors, if you want real strength and want HUGE power then sleeving the block is the best for reliability.

as for temps then you could alway's run a cooler thermostat for the cooant system, the thermostat would open sooner therfore helping keep engine temps down, also like said before larger or another oil cooler would be a good idea. i know Dinan prefer you to have there larger oil cooler for the flash but you can run just the stock one.

[chemhalo]

Originally Posted by Brandon26pdx

IIRC the Nissan RB26DETT is an open deck I-6 engine and they make big numbers with those. (Iron block however...).

Every RB26 block I can find looks like this




Although a good sign is the the VQ35 has held up to 450-500whp with boost... people run into problems with rods and pistons but no block problems.

[WhereItsAt]

There are numerous VQ35's running around 400WHP. There are not that many running above that without a built motor - at least for long . There are plenty of built VQ's running 500 or better without sleeves but the compression is around 8.5-9.3 (give or take). The VQ is proving to be a stout block. The most recent version VQ37HR is expected to handle 450WHP without touching the internals. If a NA VQ can handle that kind of power I have no reason to beleive the N54 can't. Especially now that I learned it is sleeved.

[theslik1]

Originally Posted by mkiiieustyle

i have seen alot of open deck engine make good power, but like said before it is a limiting factor, simple deck rings can be pressed in, honda's use them alot when boostin d+b series motors, if you want real strength and want HUGE power then sleeving the block is the best for reliability.

as for temps then you could alway's run a cooler thermostat for the cooant system, the thermostat would open sooner therfore helping keep engine temps down, also like said before larger or another oil cooler would be a good idea. i know Dinan prefer you to have there larger oil cooler for the flash but you can run just the stock one.

I think most of us agree that the block should be good in the 400-500 rwhp range no problem. I know I'm sounding like Chicken Little, but IMHO thermal management is the bigger issue with N54 power upgrades in that range. And no, not everyone is going limp due to overheating but it is happening often enough that it needs to be looked at as part of an integrated upgrade strategy. It may end up be a bigger issue on the 1-series simply due to tighter engine packaging and air flow restriction.

Knowing what we know right now, anything that will restrict coolant flow on the N54 is bad juju so deck rings are probably not a good idea (and not necessary anyway). A cooler thermostat won't help much...yes it will open sooner but once it is wide open it's the same amount of flow. You can safely assume that thermostats were wide open on 335's that went limp due to temperature, and temperature was still climbing. That indicates a maxed-out cooling system. A larger capacity oil cooler may end up providing the necessary margin for most of us. However, if I'm installing a larger intercooler (which may restrict air flow to the radiator) then I'm going to be looking hard at a high-capacity radiator like Fluidyne and larger cooling fans as well. None of these upgrades are uncommon, especially with turbo engines that produce elevated underhood temperatures.

I'm also curious if the 135i's front-end arrangement requires a different radiator than the 335i. It would make sense economically that it's the same unit, but who knows? :iono:

[Brandon26pdx]

Originally Posted by chemhalo

Every RB26 block I can find looks like this

Oop. I stand corrected!

[atr_hugo]

What's funny is I've helped a buddy prep Nissan I6 blocks for his racing 240Z - those things are STOUT (except that one time when he went to being 'Mr. Cheap' and reused his ARP fasteners on the conrods - nice little hole in the side of the block and a '007' oil application to the end of the main straight to boot ; -).